Composition and method for enhancing stain resistance and product of enhanced stain resistance therefrom

ABSTRACT

A fibrous polyamide or wool substrate having resistance to staining by acid colorants comprises, a fibrous polyamide or wool substrate having applied thereto a sulfonated aromatic condensation resin, said resin being a condensation product of a sulfonated dihydroxydiphenyl sulfone, a dihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde; or a sulfonated dihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde; optionally a methacrylic acid polymer is also applied thereto as well as a fluorochemical; an aqueous formulation of the resin is also provided which formulation may include the methacrylic acid polymer as well as the fluorochemical Additionally there may be employed a salt to enhance exhaustion of components onto the substrate; a method of treating a fibrous polyamide or wool substrate employing the formulation is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 11/518,501 filedSep. 11, 2006 now U.S. Pat. No. 7,648,928.

FIELD OF THE INVENTION

This invention relates to a fibrous polyamide or wool substrate havingdurable resistance to staining by acid colorants and to a compositionand method of rendering a fibrous polyamide or wool substrate durablyresistant to staining by acid colorants.

BRIEF DESCRIPTION OF PRIOR ART

Fibrous polyamide substrates, such as nylon carpeting and similar woolsubstrates are susceptible to staining by both naturally occurring andcommercial acid colorants found in many common foods and beverages. Thedemand for reduced staining from such acid colorants has by and largebeen met by treatment with compositions comprising sulfonated naphtholor sulfonated phenol-formaldehyde condensation products as disclosed forexample in the following patents: U.S. Pat. No. 4,501,591 Ucci andBlyth; U.S. Pat. No. 4,592,940 Blyth and Ucci; U.S. Pat. No. 4,680,212Blyth and Ucci; U.S. Pat. No. 4,780,099 Greshler, Malone and Zinnato;U.S. Pat. No. 4,865,885 Herlant and Al; or by treatment with compositioncomprising sulfonated novolak resins together with polymethacrylic acidas disclosed in U.S. Pat. No. 4,822,373 Olson, Chang and Muggli.

U.S. Pat. No. 6,488,893 discussed reducing polyamide fibers staining bytreating the fibres with condensation product of sulfonated naphthalenesulphonic acid, and aldehyde and a dihydroxydiphenyl sulfone togetherwith a methacrylic acid polymer.

U.S. Pat. No. 6,814,881 discussed providing anti-stain protection bytreating polyamide fibers with a condensation product of a sulfonateddihydroxydiphenyl sulfone dihydroxydiphenyl sulfone and an aldehydetogether with a methacrylic acid polymer.

The use of polymers and copolymers of methacrylic acid of low weightaverage molecular weight and low number average molecular weight isdescribed in U.S. Pat. No. 4,937,123 Chang, Olson and Muggli.

The initial stain resistance properties imparted to polyamide or woolsubstrates, such as carpeting, that have been treated using the abovementioned compositions degenerate, significantly with each wet cleaningthe substrate receives. Improved stain resistance after wet cleaning canbe achieved by increasing the amount of the sulfonated aromaticformaldehyde condensation products, in the stain resist product or byincreasing the amount of stain-resist product initially applied to thesubstrate, however, this generally leads to discoloration caused byyellowing of the substrate initially and further discoloration uponexposure to oxides of nitrogen and/or light.

Stain-resist products currently available in the market place aregenerally based on dihydroxydiphenyl sulfone and phenol sulfonic acidcondensed with an aldehyde in acid or alkaline media, ordihydroxydiphenyl sulfone and naphthalene sulfonic acid condensed withaldehyde.

It is generally known that increasing the ratio of the dihydroxydiphenylsulfone to the phenol sulfonic acid or naphthalene sulfonic acidincreases the stain resistance properties of the resin but subsequentlycauses a higher degree of yellowing or discoloration initially andfurther discoloration upon exposure to oxides of nitrogen and/or light.

Conversely it is also evident that when the ratio of phenol sulfonicacid or naphthalene sulfonic acid to dihydroxydiphenyl sulfone increasesthe result is less discoloration, but lower stain-resist properties.

The addition of a methacrylic resin in the form of methacrylic polymersand/or copolymers to the previously mentioned condensation products(novolak resin) as disclosed in U.S. Pat. No. 4,223,473 (Olson, Changand Muggli) allows the use of a novolak resin in smaller quantities withlarger quantities of the methacrylic resin. With this combination ofnovolak resin and methacrylic resin, a major improvement in the lightfastness or less discoloration is achieved due to the dramaticallyreduced percentage of novolak resin in the product mentioned above,which is adjusted to obtain a desired low level of discoloration whilemaintaining an acceptable level of durability to wash. The high level ofinitial stain resistance is supposedly maintained by the novolak resin,the methacrylic resin having largely been removed during the wetcleaning process.

U.S. Pat. No. 6,197,378 discusses the addition of salts tofluorochemical bath or fluorochemical both to improve exhaustion.

U.S. Pat. No. 5,098,774 discusses the manufacturing of condensationproduct of sulfonated dihydroxydiphenyl sulfone with formaldehydefollowed by neutralization with magnesium oxide to produce novolak saltwater soluble resin, this novolak salt resin can be used alone or withfluorochemicals to achieve good exhaustion of stain resist and water andoil repellency at the same time.

SUMMARY OF THE INVENTION

It is an object of this invention to provide fibrous polyamide or woolsubstrates having durable resistance to staining by acid colorants.

It is further object of this invention to provide a method of renderinga fibrous polyamide or wool substrate durably resistant to staining byacid colorants.

It is still a further object of this invention to provide an aqueousformulation for providing resistance to staining by acid colorants in afibrous polyamide or wool substrate.

In accordance with one aspect of the invention there is provided afibrous polyamide or wool substrate having resistance to staining byacid colorants comprising: a fibrous polyamide or wool substrate havingapplied there to a sulfonated aromatic condensation resin, said resinbeing a condensation product of a sulfonated dihydroxydiphenyl sulfone,a dihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde;or a sulfonated dihydroxydiphenyl sulfone, a sulfonated naphthalene andan aldehyde.

In accordance with another aspect of the invention there is provided amethod of imparting stain resistance to acid colorants, to a fibrouspolyamide or wool substrate comprising: contacting said fibrouspolyamide or wool substrate with a sulfonated aromatic condensationresin in an aqueous vehicle, said resin being a condensation product ofa sulfonated dihydroxydiphenyl sulfone, a dihydroxydiphenyl sulfone, asulfonated naphthalene and an aldehyde; or a sulfonateddihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde.

The condensation product can be applied alone or in combination with amethacrylic acid polymer and/or a fluorochemical.

In accordance with another aspect of the invention there is provided anaqueous formulation for providing resistance to staining by acidcolorants in a fibrous polyamide or wool substrate comprising in anaqueous vehicle a sulfonated aromatic condensation resin, said resinbeing a condensation products of a sulfonated dihydroxydiphenyl sulfone,a dihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde;or a sulfonated dihydroxydiphenyl sulfone, a sulfonated naphthalene andan aldehyde; optionally with a methacrylic acid polymer of high weightaverage molecular weight and high number average molecular weight and/oroptionally an ionic or non-ionic fluorochemical.

DETAILED DESCRIPTION OF THE INVENTION

Condensation Resin

The invention employs a sulfonated aromatic condensation resin.

The condensation resin is a condensation product of a sulfonateddihydroxydiphenyl sulfone, a sulfonated naphthalene and an aldehyde; ora sulfonated dihydroxydiphenyl sulfone, a dihydroxydiphenyl sulfone asulfonated naphthalene and an aldehyde.

The aldehyde is suitably formaldehyde or a lower alkyl aldehyde in whichthe lower alkyl moiety has 1 to 6 preferably 1 to 4 carbon atoms.

The dihydroxydiphenyl sulfone may in particular be 4,4 dihydroxydiphenylsulfone; and similarly the sulfonated dihydroxydiphenyl sulfone may, inparticular be sulfonated 4,4 dihydroxydiphenyl sulfone.

The sulfonation takes the form of sulfonic acid groups which increasethe solubility of the condensation products.

The degree of sulfonation of the sulfonated naphthalene and thesulfonated dihydroxydiphenyl sulfone is suitably between 30 to 200%,preferably 80 to 130%.

The above condensation products may suitably be bleached orsemi-bleached to remove or reduce colour, which causes the yellowstaining of nylon fibres, by techniques known in the art. By way ofexample the condensate may be bleached by addition of 0.1 to 4% byweight, sodium formaldehyde sulfoxylate or zinc formaldehyde sulfoxylatefor a period of 20 to 90 minutes at a temperature below 100° C. Thistypically reduces colour by 20 to 80% and prevents furtherdiscoloration. The bleaching or partial stripping of colour ispreferably carried out at pH lower than 7 when zinc formaldehydesulfoxylate is employed and higher than 7 when sodium formaldehydesulfoxylate is employed at a temperature of 50° C. or higher. Thereference to bleaching, stripping or partially removing colour hereinrefers to removal of the part of the colour in the condensate whichcauses the yellow staining of the fibres, bleaching, stripping orpartial removal of colour results in the condensate becoming lighter incolour.

The degree of bleaching or stripping depends upon the condensate andwhether it is condensed in acid or alkaline media; and also depends onthe stripping agent employed, for example whether it is sodium or zinc,formaldehyde sulfoxylate and the bleaching or stripping conditions, forexample pH or temperature.

The time and the temperature are important factors and the percentage ofstripping of the colour varies according to the stripping conditionsbetween 20 to 80%.

After the bleaching or stripping, even if the colour is still dark, itis observed that yellowing of the fibers is much less.

The amounts of the sulfonated aromatic condensation resin on thepolyamide substrate is dependent on the process employed for thedeposition, as is well understood by persons in the art, and thuspersons in the art will well understand the concentrations required inthe aqueous formulation based on the application technique and methodparameters employed.

The aqueous formulation is applied to the fibrous substrate byconventional procedures, for example, the substrate may be immersed in abath of the aqueous formulation, or the formulation may be exhaustedonto the substrate by foam system or spray or applied in one step withfluorochemical by exhaust, foam or spray system. Suitably the treatedsubstrate is rinsed with water and dried. The resin in the driedsubstrate may optionally be cured at an elevated temperature. The thustreated substrate retains the deposited resins.

Suitably the resins are applied to the polyamide fibre substrate in anaqueous vehicle at a pH of 1 to 10, preferably 1 to 7, more preferably1.5 to 3.

Methacrylic Polymers

Methacrylic acid polymers referred to herein contemplates homopolymersas well as copolymers with one or more comonomers.

The methacrylic acid is optionally employed in conjunction with thesulfonated condensation resin.

Completely soluble acrylic and methacrylic homopolymers and copolymersdo not have durability to wet cleaning, so that their stain resisteffect diminishes with wet cleaning; whereas completely insolubleacrylic resins have very little stain resist effect on polyamide fibers.

The methacrylic acid polymer, is suitably a homopolymer of methacrylicacid or a copolymer of methacrylic acid and at least one comonomer, forexample, ethyl acrylate, 2-ethylhexyl methacrylate, ethyl methacrylate,methyl methacrylate, butyl methacrylate isobutyl methacrylate acrylicacid, butylacrylates ethyl acrylate or a mixture of more than one ofthese monomers.

The methacrylic acid polymer suitably has a high weight averagemolecular weight (MW) of at least 50,000 to 500,000 and preferably150,000 to 250,000 preferably over 200,000 and a high number averagemolecular weight (MN) of at least 25,000 typically 25,000 to 100,000 andpreferably 25,000 to 80,000 and more preferably 30,000 to 60,000.

The methacrylic acid polymer, when employed together with semi-bleachedto bleached sulfonated aromatic condensation products are applied to thepolyamide fiber or wool substrate in an aqueous vehicle.

The amount of suitable methacrylic polymers and the semi-bleached tobleached aromatic condensation products of this invention, depositedfrom the aqueous formulation on the polyamide fibre or wool substrate isdependent on the process employed for the deposition; as is wellunderstood by persons in the art, and thus persons in the art will wellunderstand the concentration required in the aqueous formulation, basedon the application technique and method parameters employed.

The aqueous formulation is applied to the substrate by conventionalprocedures for example, the substrate may be immersed in a bath, or theaqueous formulation may be exhausted onto the substrate by foam systemor spray or applied in one step with fluorochemical by exhaust, foam,spray or padding. Suitably, the treated substrate is rinsed with waterand dried.

The treated substrate retains the deposited condensation product andmethacrylic polymers, on the fibers.

In a preferred embodiment an anionic, or non-ionic fluorochemical isalso applied to the substrate. The fluorochemical can be applied from asingle bath containing the other components to be deposited or may bedeposited from a separate bath to provide water and oil repellency andsoil resist.

A salt may be employed to enhance the exhaustion of the sulfonated resinon the substrate.

Suitable salts are mono, di- or polyvalent metal salts and ammoniumsalts, for example, alkali metal salts, alkaline earth metal salts andaluminium salts, for example aluminium formate, aluminium sulphate,sodium sulphate, magnesium sulphate, zinc sulphate, copper sulphate,ferrous sulphate, magnesium chloride, calcium chloride, sodium chloride,potassium chloride and ammonium chloride.

An acid may also be employed when the treatment is carried out at anacid pH, suitable acids include sulfamic acid, sulphuric acidhydrochloric acid, citric acid, phosphoric acid, urea sulfate, ureahydrochloride, urea phosphate, formic acid oxalic acid and acetic acid.The urea sulfate, urea hydrochloride and urea phosphate act as a sourceof the acid, i.e. sulphuric acid, hydrochloric acid and phosphoric acid.

An aqueous formulation of the methacrylic acid polymer and thesulfonated aromatic condensation resin for treating a polyamidesubstrate, typically contains an amount of the methacrylic acid polymerto deposit on the polyamide substrate of Nylon 66 at least 0.1% byweight and at least 0.3% by weight, on Nylon 6.

The sulfonated aromatic condensation resin of this invention istypically employed in the formulation in an amount to deposit at least0.03% by weight, on Nylon 66 substrate and at least 0.1% by weight onNylon 6 substrate, based on the weight of the substrate.

In a particular embodiment there is deposited on Nylon 66, thesulfonated aromatic condensation resins of the invention in an amount ofat least 0.1% based on the weight of the substrate, together with atleast 0.2% based on the weight of the substrate of the methacrylic acidpolymer.

In a particular embodiment, the condensation product is neutralized, byway of example the neutralization may be with caustic soda, potassiumhydroxide, or aqueous ammonia to form a condensated aromatic neutralizedresin, water soluble at pH 1-10 preferably, 3-7 more preferably 3-5. Ina further particular embodiment, the neutralization may be with a metaloxide or hydroxide, for example oxides or hydroxides of magnesium,calcium, zinc or other metal oxides or hydroxides. Particular examplesof metal oxides or hydroxides are aluminium hydroxide, aluminatrihydrate, magnesium oxide, barium oxide, barium hydroxide, calciumoxide, zinc oxide or other heavy alkaline metal hydroxides or oxides. Inthe case of neutralized condensation product, the exhaust bath maycontain the neutralized condensation product, the methacrylic polymer,and the fluorochemical and the addition of a salt may not be required.

In another particular embodiment there is deposited on Nylon 6, thesulfonated aromatic condensation resin in an amount of at least 0.2%together with at least 0.4% of the methacrylic acid polymer. Thesulfonated aromatic condensation resin of this invention can be made asfollow:

Into a clean glassline reactor equipped with mechanical stirrer toproduce efficient agitation, the following were as charged, amountsbeing indicated in parts by weight:

-   -   7.5 parts of acetic acid anhydride    -   15 parts 4.4 dihydroxydiphenyl sulfone    -   7.5 parts sulphuric acid (99% concentration)    -   The reactor was heated to 100° C. and the stirring is continued        for 6 hours at 100° C.    -   This reaction produces 4.4 sulfonated dihydroxydiphenyl sulfone    -   The degree of sulfonation of the above product is between 100        and 200%    -   Once the reaction is completed, the reaction product is cooled        down to 80° C.

Then, additional ingredients are added as follows, amounts beingindicated in parts by weight:

-   -   4.5 parts sulfonated naphthalene    -   5.25 parts dihydroxydiphenyl sulfone    -   7.5 parts water    -   8 parts formaldehyde (37% concentration in water)

After this addition stirring continued for 30 minutes at 80° C. Then thetemperature was increased to 100 to 105° C. and the stirring continuedfor 6 hours at 100 to 105° C.

Then, the reacted product was cooled to 70° C. and neutralized withmagnesium oxide while distilling the acetic acid to pH between 1-8,preferably 3-5 then bleached with sodium formaldehyde sulfoxylate orzinc formaldehyde sulfoxylate for 30 minutes at 70° C.

The amounts of the sulfonated dihydroxydiphenyl sulfone, thedihydroxydiphenyl sulfone, the sulfonated naphthalene and theformaldehyde may be adjusted to provide sulfonated condensation resinsof different solubilities and different molecular weight while ensuringthat the resin product is effective to block the dye sites of thepolyamide and provides good durability.

For comparison with the resin of the invention, there was considered amixture of resins, the first resin of the mixture being a condensationresin of sulfonated naphthalene, 4,4-dihydroxydiphenyl sulfone andformaldehyde and the second resin of the mixture being a condensationresin of sulfonated 4,4-dihydroxydiphenyl sulfone and formaldehyde. Theindividual resins which in admixture are employed in examples # 5 and #14 below are made as follows:

First resin, the naphthalene condensate; In a glass lined reactor therewas charged, with amounts indicated in parts by weight: 15 parts ofrefined naphthalene and 16 parts of sulphuric acid (concentration 99%)the resulting charge was mixed for 6 hrs at 160° C. The resultingproduct was a sulphonated naphthalene. The temperature of the reactionmixture was adjusted to 80° C., then there was added 10 parts of4,4-dihydroxydiphenyl sulfone, 4.5 parts of water, 8.6 parts offormaldehyde (concentration 37%) and the temperature was increased to115° C. with mixing for 6 hrs, whereafter the mix was cooled to 80° C.and there was added: 29.9 parts of water, and 16 parts of ammonia.

The second resin was made as follows, with amounts indicated in parts byweight: 10 parts acetic acid anhydride, 20 parts 4,4-dihydroxydiphenylsulfone and 10 parts sulphuric acid, the above mix was heated to 100° C.and mixed for 6 hrs, then cooled down to 80° C., then there was added:7.7 parts water and 5.8 parts formaldehyde (concentration 37%); theresulting mixture was mixed for 6 hrs, then cooled down to 80° C., thenthere was added: 7.7 parts of water and 5.8 parts formaldehyde(concentration 37%); the resulting mixture was mixed for 6 hrs at100-105° C. then neutralized with caustic soda and the product wasadjusted to 100 parts with water.

Test Methods

In the test procedures and examples described below all percentages areby weight unless otherwise indicated, the molecular weight (MW) is theweight average molecular weight, and the molecular weight (MW) is theweight average molecular weight, and the molecular weight (MN) is thenumber average molecular weight.

Initial Stain Resistance (“IS”)

A 5″×5″ sample of the substrate to be tested is placed on a flat,non-absorbent surface. A two inches diameter ring is placed on thesample and 20 ml of staining solution is poured into the ring and workedinto the substrate. The ring is removed and the sample is leftundisturbed for 16 hours at ambient temperature. The staining solutionis prepared by dissolving 0.6 grams of Acid Red Dye No. 40, the sampleis rinsed with cool tap water and dried.

The stain resistance of the sample is visually rated by assessing theamount of colour remaining in the stained area by comparison with theunstained portion. The sample is rated on a scale from 1 to 10 isexcellent stain resistance and 1 is poor stain resistance categorized asfollows:

-   -   10. Excellent stain resistance    -   09. Good stain resistance    -   08. Acceptable stain resistance    -   07. Poor stain resistance    -   06. Unacceptable staining    -   05. Unacceptable staining    -   04. Unacceptable staining    -   03. Unacceptable staining    -   12. Unacceptable staining    -   01. Unacceptable staining        After Wet Cleaning Stain Resistance (“WS”)

The sample to be tested is first immersed in a detergent solutioncontaining 15 grams of Duponol Waqe (Trade Mark of E.I. DuPont deNemours a surface active agent based on lauryl sulfate) per liter ofwater at a pH of 10 and at 20° C. for 15 minutes. The sample is removedfrom the detergent solution and rinsed thoroughly with cool tap waterand dried. The staining solution is then applied and evaluated as setout in the initial stain resistance procedure.

Initial Yellowing (Discoloration) Evaluation (“ID”)

In the examples a graduated scale from 1 to 5 was used to evaluateyellowing where 5 represents no yellowing 4 represents acceptableyellowing and 3 or less represents unacceptable yellowing.

Discoloration Upon Exposure to Light (“LD”)

In the examples a graduated scale from 1 to 5 was used to evaluatediscoloration upon exposure to light where 5 represents no discoloration4 represents acceptable discoloration and 3 or less representsunacceptable discoloration. Exposure to light was carried out accordingto AATCC test method 16E with an exposure time of 40 standard hours.

Water and oil repellency test method start with the lowest numbered testliquid. Carefully place one drop of the test liquid in several locationon the surface, repeat with higher number liquid until the highestnumber reached does not wet the surface in 30 second for oil and 10second for water.

Water (Liquid) Test

Water rating number Isopropanol Water 1 2 98 2 5 95 3 10 90 4 20 80 5 3070 6 40 60Oil (Liquid) Test

Oil rating number Composition 1 Laydol (mineral oil) 2 65/35 Kydol/N -Hexadelane 3 N - Nexadelane 4 N - Tetradelane 5 N - Dodelane 6 N -Delane

The sulfonated aromatic condensation product alone and with themethacrylic polymer were tested as follows:

Test on Nylon 66

The treatment bath was adjusted to pH 1.8 by Bartex C-4 (Trade-mark forbuffering system from Trichromatic Carpet under U.S. Pat. No. 5,821,177)

In each case Nylon 66 substrate was immersed in the stain resist bath toobtain a pick up of about 350% on the weight of the substrate, thensteamed for 3 minutes, followed by light rinse and dried to be ready fortesting. The results appear in Table 1.

The amount of stain blocker used were as follows, where % are by weight:

EXAMPLE # 1

4 g/L condensation product of this invention at 40% solid.

EXAMPLE # 2

4 g/L of a condensation product of a sulfonated dihydroxydiphenylsulfone 40% solids.

EXAMPLE # 3

4 g/L of a condensation product of a sulfonated naphthalene anddihydroxydiphenyl sulfone 40% solids.

EXAMPLE # 4

4 g/L of a condensation product of a phenol sulfonic acid and adihydroxydiphenyl sulfone 40% solids.

EXAMPLE # 5

4 g/L of a mixture of 50% by weight, of a condensation product of asulfonated dihydroxydiphenyl sulfone, and 50% by weight of acondensation product of a sulfonated naphthalene and a dihydroxydiphenylsulfone.

EXAMPLE # 6

6 g/L of a product made by adding 15% by weight of the product of thisinvention and 85% by weight of methacrylic acid copolymer of 20% solidand 40,000 M.N.

EXAMPLE # 7

6 g/L of a mixture of 15% of a sulfonated dihydroxydiphenyl sulfonecondensate and 85% of a methacrylic acid copolymer as in Example 6above.

EXAMPLE # 8

6 g/L of a mixture of 15% of a condensation product of a sulfonatednaphthalene and a dihydroxydiphenyl sulfone and 85% of a methacrylicacid copolymer as in Example 6 above.

EXAMPLE # 9

6 g/L of a mixture of 15% of a dihydroxydiphenyl sulfone and a phenolsulfonic acid condensate and 85% of a methacrylic acid copolymer as inExample 6 above.

Test on Nylon 6

In each case Nylon 6 substrate was immersed in the stain resist bath toobtain a pick up of 350% by weight based on the weight of the substrate,then steamed for 3 minutes, followed by light rinsing and drying so asto be ready for testing dried to be ready for testing. The resultsappear in Table # 2:

EXAMPLE # 10

6 g/L of a condensation product of this invention at 40% solids.

EXAMPLE # 11

6 g/L of a condensation product of sulfonated dihydroxydiphenyl sulfone.

EXAMPLE # 12

6 g/L of a condensation product of a sulfonated naphthalene and adihydroxydiphenyl sulfone at 40% solids.

EXAMPLE # 13

6 g/L of a condensation product of a phenol sulfonic acid and adihydroxydiphenyl sulfone at 40% solids.

EXAMPLE # 14

6 g/L of the resin mixture of example # 5.

EXAMPLE # 15

10 g/L of a mixture of 15% of a condensation product of this inventionand 85% of a methacrylic acid copolymer 20% solid and 40,000 MN.

EXAMPLE # 16

10 g/L of 15% condensation product of sulfonated dihydroxydiphenylsulfone and 85% methacrylic acid copolymer as in Example 15 above.

EXAMPLE # 17

10 g/L of a mixture of 15% of a condensation product of naphthalenesulfonic acid and a dihydroxydiphenyl sulfone and 85% of a methacrylicacid copolymer as in Example 15 above.

EXAMPLE # 18

10 g/L of a mixture of 15% of a condensation product of phenol sulfonicacid and dihydroxydiphenyl sulfone and 85% of a methacrylic acidcopolymer as in Example 15 above.

EXAMPLE # 19

6 g/l of a mixture of 40% of the condensation product of this inventionneutralized by sodium hydroxide and 60% methacrylic acid polymer isapplied on Nylon 6 as described in the test method with additional 5 g/lnon-ionic fluorochemical has 9% fluorine content.

EXAMPLE # 20

6 g/l of a mixture of 40% of the condensation product of this inventionneutralized by magnesium oxide and 60% methacrylic acid polymer isapplied on nylon 6 as described in the test method with additional 5 g/lnon-ionic fluorochemical has 9% fluorine content.

TABLE 1 IS WS ID LD Example 1 8 7-8 4-5 4-5 Example 2 8 7-8 3-4 3-4Example 3 7 6 4 4 Example 4 7-8 6-7 3-4 3-4 Example 5 8 7 3-4 3-4Example 6  9-10 7-8 5 5 Example 7 9 7-8 4 4 Example 8 7-8 6 4-5 4-5Example 9 7-8 6-7 4 4

TABLE 2 IS WS ID LD Example 10 8-9 7-8 4-5 4-5 Example 11 8-9 7-8 3-43-4 Example 12 7 6 4-5 4-5 Example 13 7 6-7 3-4 3 Example 14 8 7 3-4 3-4Example 15  9-10 8 5 5 Example 16 9 7-8 3-4 3-4 Example 17 7-8 6 4-5 4-5Example 18 8 6-7 3-4 3-4

TABLE 3 Water Oil IS WS ID LD repellency repellency Example 8-9 7-8 4-54-5 3 3-4 19 Example  9-10 8 4-5 4-5 4-5 4-5 20Results

-   -   1) The results in Table 1 of the treatment of stain blocker on        nylon 66 show the following:        -   a. Best results of anti-stain and wash durability provided            by products of examples # 1, 2, 6 and 7.        -   b. Best light fastness and non-yellowing were provided by            products of examples # 1, 6 and 8.    -   2) The results of table 2 of the treatment of stain blocker on        nylon 6 shows the following:        -   c. Best results of anti-stain and wash durability were            provided by products of examples # 10, 11, 15 and 16.    -   3) It is clear that the lowest yellowing on carpet and the best        light fastness are for the carpets treated with the product of        this invention.    -   4) It was noticed that the product of example 5 and 14 which        contains a mixture of:        -   a. Condensation product of sulfonated dihydroxydiphenyl            sulfone and:        -   b. Condensation product of sulfonated naphthalene and            dihydroxydiphenyl sulfone did not perform as well as the            condensation resins of this invention, in the staining or            the yellowing.    -   5) The second best product for the non-yellowing and light        fastness is the one containing sulfonated naphthalene,        dihydroxydiphenyl sulfone and formaldehyde.

However, the product of this invention is superior in initial stainingand the wash durability and has equal or superior light fastness and nonyellowing.

-   -   6) It was noticed that when the resin of this invention        neutralized with magnesium oxide, it improved the initial        staining and wash durability. Also, when a fluorochemical is        presented in the bath the resin neutralized with magnesium oxide        shows a better exhaustion of the fluorochemical on the polyamide        fibers.

While the invention has been particularly described by reference to afibrous polyamide substrate, it applied equally to a wool substrate forthe application of the condensation products.

It will be recognized that various modifications and alterations of theinvention will be apparent to those skilled in the art withoutdepartment from the scope and spirit of the invention and that theinvention is not restricted by the details and examples set forth forillustrative purposes.

1. An aqueous formulation for providing resistance to staining by acidcolorants in a fibrous polyamide or wool substrate comprising in anaqueous vehicle: a sulfonated aromatic condensation resin, said resinbeing a condensation product of: i) a sulfonated dihydroxydiphenylsulfone; ii) a dihydroxydiphenyl sulphone; iii) a sulfonated naphthaleneand iv) an aldehyde.
 2. An aqueous formulation according to claim 1,further comprising a methacrylic acid polymer having a weight averagemolecular weight of 50,000 to 500,000 and number average molecularweight of 25,000 to 150,000.
 3. An aqueous formulation according toclaim 2, wherein the methacrylic acid polymer has a number averagemolecular weight of 30,000 to 60,000.
 4. An aqueous formulation forproviding resistance to staining by acid colorants in a fibrouspolyamide or wool substrate comprising in an aqueous vehicle: asulfonated aromatic condensation resin, said resin being a condensationproduct of: i) a sulfonated dihydroxydiphenyl sulfone; ii) adihydroxydiphenyl sulphone; iii) a sulfonated naphthalene and iv) analdehyde, wherein said aqueous vehicle contains said condensation resin,a methacrylic acid polymer having a weight average molecular weight of50,000 to 500,000 and a number average molecular weight of 25,000 to150,000, a fluorochemical, an acid and a salt.
 5. An aqueous formulationaccording to claim 4, wherein said acid is selected from sulfamic acidsulphuric acid, citric acid, phosphoric acid, urea sulphate, ureahydrochloride, urea phosphate, formic acid or acetic acid and said saltis selected from mono, di, or polyvalent metal salts.
 6. An aqueousformulation according to claim 5, wherein said salt is an alkaline earthmetal salt or an aluminium salt.
 7. An aqueous formulation according toclaim 6, wherein said salt is aluminium formate or aluminium sulphate.8. An aqueous formulation according to claim 4, having a pH of 1 to 7.9. An aqueous formulation according to claim 2, wherein the degree ofsulfonation of the sulfonated naphthalene and the sulfonateddihydroxydiphenyl sulfone is between 30 to 200% .
 10. A method ofimparting stain resistance to acid colorants, to a fibrous polyamide orwool substrate comprising: contacting said fibrous polyamide or woolsubstrate with a sulfonated aromatic condensation resin in an aqueousvehicle, said resin being a condensation product of: i) a sulfonateddihydroxydiphenyl sulfone; ii) a dihydroxydiphenyl sulfone; iii) asulfonated naphthalene and iv) an aldehyde.
 11. A method according toclaim 10, wherein said substrate is additionally contacted with amethacrylic acid polymer having a weight average molecular weight of50,000 to 500,000 and number average molecular weight of 25,000 to150,000.
 12. A method according to claim 10, wherein said substrate iscontacted with said aqueous vehicle by foam, spray, paddling or anexhaust method; said aqueous vehicle additionally containing methacrylicacid polymer having a weight average molecular weight of 50,000 to500,000 and number average molecular weight of 25,000 to 150,000; afluorochemical; an acid and a salt, and said vehicle has a pH of 1 to 7.13. A method according to claim 10, wherein said substrate is contactedwith said aqueous vehicle in an aqueous bath which additionally containsa methacrylic acid polymer having a weight average molecular weight of50,000 to 500,000 and a number average molecular weight of 25,000 to150,000 and a fluorochemical.
 14. A method according to claim 12,wherein the substrate is contacted with the aqueous vehicle by immersingthe substrate in the aqueous vehicle followed by steaming, rinsing anddrying the substrate.
 15. A method according to claim 14, wherein thedrying is followed by curing at an elevated temperature.
 16. A methodaccording to claim 12, wherein the degree of sulfonation of thesulfonated naphthalene and the sulfonated dihydroxydiphenyl sulfone isbetween 30 to 200% .